So far, NO ONE is saying it should be smaller, which suggests to me that this is as small as you could reasonably go. Therefore, the font is clearly on the small end and one could reasonably justify it to be enlarged by one point.

I posted the poll to get a sense of others' viewpoints on it. Next time I notice it's a tad small, I can say to myself, "Hey, a slim majority think it's just fine, so it should be fine for me too, just like how slim majorities often win elections." ... wait, maybe that wasn't what I was going for. ... yeah, screw it, dictatorship is best after all.

I'm not sure what are you seeing when you zoom in, but on my 13" MacBook (1280x800) zoom works just fine: by default it zooms "everything" (fixed width css or not, the result would be the same) and if I instead switch to zooming text only, it doesn't break in any way either (Safari).